Two dry-cow therapy products were evaluated in seven factory-supply dairy herds in the Waikato area. A product containing neomycin sulphate and the benzathine salt of penicillin (Neopen D.C. White; Smith-Biolab) was used in five herds, and one containing benzathine cloxacillin (Orbenin, Beecham) was used in two herds. Non-treated control cows were included in each herd. Both products were effective in eliminating intramammary infections withStaphylococcus aureus, Streptococcus uberis, andStreptococcus agalactiae. Efficacy of dry-cow therapy againstS. aureuswas 83.8% and 85.2% respectively. Spontaneous cure rate among controls was 30.8% forS. aureusduring the dry period. Spontaneous cure rate forStr. uberiswas 50%, while dry-cow therapy eliminated 100% and 77.8%, respectively, for the two products. Dry-cow therapy with either product eliminated more than 90% ofStr. agalactiaeinfections while spontaneous cure rate was only 28.6%. These results further support the effectiveness of dry-cow therapy in reducing the level of subclinical mastitis in dairy herds by shortening the duration of intramammary infections.